Ski binding for a cross country ski or touring ski

ABSTRACT

A ski binding for a cross country ski or touring ski (1). The ski binding includes a swivel part (40) and a holding cup (50) both pivotal about a transversely extending first axle (3) against the force of an elastic element in unison as well as with respect to one another. The swivel part (40) is constructed as a two-arm toggle lever and carries therewith a locking pin (42) on a first lever arm (41) thereof and a second axle (7) for a lock part (60) on a second lever arm (43) thereof. The holding cup (50) has in a front area thereof a crossbar (54) connecting its sidewalls (52), which crossbar is constructed as a locking nose (55) at its front end. The locking nose is defined by a first arcuate surface (56) extending around the transversely extending first axle (3) and a contiguous arcuate holding surface (57). A lock part (60) is provided and includes an arcuate surface region (61 ) around the second axle (7). When the ski binding is in the closed position, tangential planes tangent to the arcuate holding surface (57) and to the arcuate surface region (61) define an acute angle (α) with one another.

The invention relates to a ski binding for a cross country ski ortouring ski.

BACKGROUND OF THE INVENTION

Such a ski binding is described in the WO 87/03211 (corresponding toU.S. Pat. No. 4,993,742) The sidewalls of the holding cup are connectedby a crossbar in this known ski binding, which crossbar has a lockinggroove. The swivel part, which is pivotal with a holding cup about acommon transversely extending axle carries on its upwardly directedextension an axle to which a lock part with a locking nose is hinged.The locking nose extends into the locking groove of the crossbar of theholding cup when the ski binding is closed. Such a cross country skibinding with the cross country ski boot, which fits the binding, canalso be obtained commercially and has proven to be successful inpractice.

However, it has been found that the closing of the binding may possiblybe difficult when snow, ice or dirt has accumulated or been compactedunder the holding cup or under the cross country ski boot during astepping into the binding. The holding cup is in such a case notcompletely swung down and the locking nose of the lock cannot fullyextend into the locking groove of the holding cup. The locking nose ofthe lock presses onto the crossbar caused by the force of the lockingspring, however, an unintended opening of the ski binding can occur inthe case of very strong vibrations.

The purpose of the invention is to improve the known ski binding suchthat a reliable closing of the same occurs even when snow, ice or dirtaccumulations prevent the complete downward swing of the holding cup. Inparticular a stepless adjustment of the lock part is thereby desired incase the amount of snow or dirt under the holding cup becomes slowlyworn away during skiing. Furthermore, the entire height of the skibinding is less.

SUMMARY OF THE INVENTION

The objects and purposes of the invention have been met by providing aski binding for a cross country ski or touring ski. The ski bindingincludes a swivel part and a holding cup both pivotal about atransversely extending first axle against the force of an elasticelement in unison as well as with respect to one another. The swivelpart is constructed as a two-arm toggle lever and carries therewith alocking pin on a first lever arm thereof and a second axle for a lockpart on a second lever arm thereof. The holding cup has in a front areathereof a crossbar connecting its sidewalls, which crossbar isconstructed as a locking nose at its front end. The locking nose isdefined by a first arcuate surface extending around the transverselyextending first axle and a contiguous arcuate holding surface. A lockpart is provided and includes an arcuate surface region around thesecond axle. When the ski binding is in the closed position, tangentialplanes tangent to the arcuate holding surface and to the arcuate surfaceregion define a forwardly open acute angle α in a range of 1 to 15degrees (preferably 3 to 10 degrees) with respect to one another.

Due to the face that the holding cup has in its front region a crossbarconnecting its sidewalls, which crossbar is constructed as a lockingnose having at its front end a first surface extending approximately inthe form of a cylindrical sleeve section extending around thetransversely extending axle and with a contiguous second surfacedesigned like a further cylindrical sleeve section and extending indirection of the transversely extending axle and operating as a holdingsurface, that the lock has a locking region arranged around the lockingaxle along a cylindrical sleeve section, and that, viewed in the closedand not stressed position of the ski binding, the axis of thecylindrical sleeve section forming the holding surface is spacedforwardly from the axle of the cylindrical sleeve section forming thelocking region, it is guaranteed that even without a complete downwardswinging of the holding cup the locking region of the lock part gripssufficiently far under the holding surface of the locking nose that areliable closing of the ski binding is assured. The design of theholding surface in the form of a cylindrical sleeve section, with thetangential planes tangent to the holding surface and to the lockingregion defining an acute angle with one another, enables the steplessmoving up of the lock part in closing direction when the accumulation ofdirt below the cup becomes less.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages, characteristics and details of the invention will bedescribed hereinafter in greater detail in connection with the drawingswithout being limited to these drawings. In the drawings:

FIG. 1 is a longitudinal cross-sectional view of an embodiment of thecross country ski binding embodying the invention, namely, in a positionwhere it is ready to be stepped into,

FIG. 2 shows the cross country ski binding of FIG. 1 in the closed,however, not stressed position (sliding position), and

FIG. 3 shows the cross country ski binding of FIG. 2, however, with dirtor ice having accumulated below the cup, and

FIGS. 4, 5 and 6 show each a detail of the ski binding of the inventionin an enlarged scale.

DETAILED DESCRIPTION

The terms front, rear, above, below in the following description are tobe understood from the standpoint of the user; namely, front meanstoward the tip of the ski.

A bearing block 30 is mounted on a ski 1 by means of schematicallyindicated screws 2. It consists substantially of a base plate 31 andsidewalls 32. The sidewalls 32 support a transversely extending axle 3.A swivel part 40 is hinged to the transversely extending axle 3. Theswivel part 40 is designed as a toggle lever, with its first lever arm41 extending rearwardly and carrying an upwardly directed locking pin42, while the second lever arm 43 is inclined forwardly and downwardly.The second lever arm 43 has a support surface 44 and a projection 45 fora spring on its downwardly and rearwardly directed side, which spring 5is arranged in an elongated recess 33 of the base plate 31. The spring 5is designed as a compression spring in this exemplary embodiment and issupported at one end thereof on the support surface 44 of the swivelpart 40 and at the other end on a rear boundary wall 34 of the elongatedrecess 33.

The transversely extending axle 3 supports furthermore a holding cup 50to receive a cross country ski boot 20. The holding cup 50 has anopening 51 for the locking pin 42. Guide bars 53 are connected at thetop of the sidewalls 52 of the holding cup 50. The sidewalls 52 of theholding cup 50 are connected in their front part by a crossbar 54. Thecrossbar 54 is designed as a locking nose 55 at its front end, with itsfirst surface 56 extending approximately like a cylindrical sleevesection around the transversely extending axle 3. A second surface or aholding surface 57 follows, which second surface or holding surface isalso designed as a cylindrical sleeve section having a radius r_(H) andextends approximately in direction of the transversely extending axle 3.The exact design and position of the surfaces 56 and 57 and theassociated axes can be recognized more clearly in FIG. 4.

An expanding spring 6 is arranged around the transversely extending axle3 and continually urges the swivel part 40 and the holding cup 50 inopposite directions about the axle.

A locking axle 7 extending transversely with respect to the longitudinaldirection of the ski is arranged on the second lever arm 43 of theswivel part 40. The locking axle 7 carries a lock part 60 which has alocking region 61 and a recess 62 thereon. The recess 62 enables theinsertion of the tip of a ski pole thereinto for the voluntary openingof the ski binding. The locking region 61 is arranged along acylindrical sleeve surface having a radius r_(R), the axis of whichcoincides with the locking axle 7. FIG. 4 also shows that the axis 9 ofthe cylindrical sleeve section forming the holding surface 57 lies infront of the locking axle 7 in the sliding position of the ski binding.An unobstructed surface portion 63 is provided below the locking region61. A locking spring 8 is arranged around the locking axle 7 tocontinually urge the lock part 60 in a closing direction.

FIG. 1 shows furthermore the front area of the cross country ski boot 20having a sole 21 and a hook element 22 illustrated by dash-dotted linesin the drawings. This cross country ski boot 20 is known, is not part ofthe subject matter of this invention and is, therefore, not described indetail.

FIG. 1 shows the cross country ski binding of the invention ready to bestepped into and with an inserted cross country ski boot 20. The holdingcup 50 is, during a lowering of the cross country ski boot 20, swungdownwardly against the force of the expanding spring 6, with the lockingpin 42 penetrating through the opening 51 in the holding cup 50 andextending into the opening existing between the sole 21 and the hookelement 22. The first surface 56 of the locking nose 55 slides at thesame time along the surface portion 63 of the lock part and thus makesit possible that the locking spring 8 swings the lock part 60 in theclosing direction until the locking region 61 of the lock part 60engages the holding surface 57 of the holding cup 50. This position isillustrated in FIG. 2. Thus the holding cup 50, the swivel part 40 andthe lock 60 form a unit moving with the cross country ski boot 20. FIG.4 shows that the holding surface 57 and the locking region 61 engage oneanother at the point P.

FIG. 3 illustrates a cross country ski binding in the closed positionsimilar to FIG. 2, with packed snow having been collected below theholding cup 50, however, preventing a complete swinging down of theholding cup. FIG. 3 and the associated enlarged illustration accordingto FIG. 5 show that the locking region 61 of the lock part 60 engagesthe holding surface 57 of the holding cup 50 at a different point,namely P', than that of the case in the situation illustrated in FIG. 2and 4, where the holding cup 50 is completely swung down. Of course,depending on the amount of packed snow collected below the holding cup50, different angles of traverse and thus different points of engagementare possible. The inventive design of the holding surface 57 and of thelocking region 61 guarantees, even when the ski binding or the boot soleis rather dirty, that the holding surface 57 still sufficiently gripsover the locking region 61. A play-free cooperation between the holdingsurface 57 and the locking region 61 is thereby assured in everyconceivable position. The lock part is automatically moved into aclosing direction by the locking spring 8 when the packed snow below theholding cup 50 is slowly worn away during cross country skiing.

FIG. 6 illustrates the locking region 61 and the locking nose 55 at thepoint of opening. The ski binding is opened by pivoting the lock part60, by, for example, pressing the tip of a ski pole into the recess 62of the lock part 60.

Of course, the invention is not to be limited to the described exemplaryembodiment illustrated in the drawings. Rather modifications of the sameare possible without departing from the scope of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A ski binding for across country or touring ski comprising a bearing block adapted to besecured to a ski, said bearing block having a horizontally transverselyextending first axle thereon, a holding cup and a two-arm swivel partpivotally supported for movement about said horizontally transverselyextending first axle in unison as well as with respect to one anotherfor the purpose of transitioning between a closed and an open positionof the ski binding, a first lever arm of said swivel part carrying atleast one locking pin, said holding cup having means defining an openingfor receiving therein said at least one locking pin in the closedposition of the ski binding, said locking pin being fixed by a yieldablelock, said holding cup being further adapted to grip over a front soleextension of a ski boot while said locking pin also extends through anopening in an extension of the front sole of the ski boot, whereas inthe open position of the ski binding, said locking pin is removed frominside of said opening on said holding cup, an elastic element forresisting said pivoting of said holding cup and said swivel part aboutsaid transversely extending first axle, a second lever arm of saidswivel part having a second axle thereon, said yieldable lock includinga lock part pivotally mounted on said second axle for engaging saidholding cup in the closed position of the ski binding and a spring forurging said holding cup and said swivel part apart, wherein said holdingcup has a transversely extending crossbar connecting its sidewalls in afront area thereof, wherein said crossbar has at a front facing endthereof a locking nose which has a first arcuate surface extendingaround said transversely extending first axle and a second arcuatesurface contiguous with said first surface and extending generally in adirection of said transversely extending first axle and operating as aholding surface, wherein said lock part has an arcuate surface regionarranged around said second axle, and wherein, when said ski binding isin the closed position, planes tangential to said arcuate holdingsurface and to said arcuate surface region define with one another anarcuate, forwardly open angle (α) in a range of 1° to 15°.
 2. The skibinding according to claim 1, wherein said holding surface is a sleevesection of a circular cylinder, an axis of which, when the ski bindingis in the closed position, lies in front of said second axle.
 3. The skibinding according to claim 1, wherein said second lever arm on saidswivel part, when the ski binding is in a closed and non-stressedposition, extends downwardly and forwardly, and wherein said second axleextends in a horizontal plane oriented below a horizontal planecontaining said transversely extending first axle.
 4. The ski binding toclaim 1, wherein said angle (α) is in the range of 30° to 10°.